[Elecraft] Re: K3 Reference Oscillator
49.380 MHz. All signal sources are phase-locked to the refernce. Fine adjustment occurs in firmware, and once calibrated, it's accurate to about 1 Hz through 6 meters at the calibration temperature. The high-stability option is at the same frequency, with firmware correction to better than 0.5 ppm. 73, Wayne N6KR On Aug 29, 2007, at 8:51 AM, Ron Durie wrote: What is the operating frequency of the K3 TCXO reference oscillator? --- http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] Re: K3 Reference Oscillator
Wayne, given that 49.380 isn't a readily available calibration freq like, say, WWV, how does a ham in the field check or set it if needed? 73, Bob N6WG - Original Message - From: wayne burdick [EMAIL PROTECTED] To: Ron Durie [EMAIL PROTECTED] Cc: Elecraft@mailman.qth.net Sent: Wednesday, August 29, 2007 8:59 AM Subject: [Elecraft] Re: K3 Reference Oscillator 49.380 MHz. All signal sources are phase-locked to the refernce. Fine adjustment occurs in firmware, and once calibrated, it's accurate to about 1 Hz through 6 meters at the calibration temperature. The high-stability option is at the same frequency, with firmware correction to better than 0.5 ppm. 73, Wayne N6KR On Aug 29, 2007, at 8:51 AM, Ron Durie wrote: What is the operating frequency of the K3 TCXO reference oscillator? --- http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] Re: K3 Reference Oscillator
Hi Bob, You can tune in a reference signal of your choice and adjust the REF CAL menu entry in real-time. You can even turn SPOT on while in the menu entry, then tune for zero beat. Works very well. 73, Wayne N6KR On Aug 29, 2007, at 9:04 AM, Robert Tellefsen wrote: Wayne, given that 49.380 isn't a readily available calibration freq like, say, WWV, how does a ham in the field check or set it if needed? 73, Bob N6WG --- http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] Re: K3 Reference Oscillator
At 11:59 AM 8/29/2007, wayne burdick wrote... 49.380 MHz. All signal sources are phase-locked to the refernce. Fine adjustment occurs in firmware, and once calibrated, it's accurate to about 1 Hz through 6 meters at the calibration temperature. The high-stability option is at the same frequency, with firmware correction to better than 0.5 ppm. 49,380,000 * 0.005 ppm = 24.69 Hz, and actually worse on 6 meters, since it's a higher frequency. In any case, it's considerably worse that the 1 Hz stated for the standard reference. Is that ppm/degree C, over some temperature range, or ? Is the tempco specified for the standard reference? ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] Re: K3 Reference Oscillator
Bob: REALLY SIMPLE! Go to CW mode, go to the highest WWV freq. you can hear, turn SPOT on and then crank on the REF CAL menu value until you hear dead zero beat. Tom At 11:04 08/29/2007, you wrote: Wayne, given that 49.380 isn't a readily available calibration freq like, say, WWV, how does a ham in the field check or set it if needed? 73, Bob N6WG - Original Message - From: wayne burdick [EMAIL PROTECTED] To: Ron Durie [EMAIL PROTECTED] Cc: Elecraft@mailman.qth.net Sent: Wednesday, August 29, 2007 8:59 AM Subject: [Elecraft] Re: K3 Reference Oscillator 49.380 MHz. All signal sources are phase-locked to the refernce. Fine adjustment occurs in firmware, and once calibrated, it's accurate to about 1 Hz through 6 meters at the calibration temperature. The high-stability option is at the same frequency, with firmware correction to better than 0.5 ppm. 73, Wayne N6KR On Aug 29, 2007, at 8:51 AM, Ron Durie wrote: What is the operating frequency of the K3 TCXO reference oscillator? --- http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] Re: K3 Reference Oscillator
Mike, Maybe I wasn't clear on this. I said it was accurate to 1 Hz ... at the calibration temperature. That says nothing about what happens as the temperature *changes*. +/- 0.5 ppm (or +/- 1 PPM) is the most common high-stability reference option available for ham transceivers, K3 included. (And yes, this applies to the entire temperature range, not per degree C.) The K3 has an advantage over most transceivers in this regard. The REF CAL menu entry can be used to enter frequency-vs.-temp data that's supplied with each individual 1 PPM oscillator. This data is used in conjunction with an accurate temperature sensor to fine-tune the reference in 0.2-Hz steps as the temperature changes. So we're actually expecting something like +/- 0.2 ppm over temperature. But we're specifying it conservatively. 73, Wayne N6KR On Aug 29, 2007, at 9:29 AM, Mike S wrote: At 11:59 AM 8/29/2007, wayne burdick wrote... 49.380 MHz. All signal sources are phase-locked to the refernce. Fine adjustment occurs in firmware, and once calibrated, it's accurate to about 1 Hz through 6 meters at the calibration temperature. The high-stability option is at the same frequency, with firmware correction to better than 0.5 ppm. 49,380,000 * 0.005 ppm = 24.69 Hz, and actually worse on 6 meters, since it's a higher frequency. In any case, it's considerably worse that the 1 Hz stated for the standard reference. Is that ppm/degree C, over some temperature range, or ? Is the tempco specified for the standard reference? --- http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] Re: K3 Reference Oscillator
At 12:48 PM 8/29/2007, wayne burdick wrote... Maybe I wasn't clear on this. I said it was accurate to 1 Hz ... at the calibration temperature. That says nothing about what happens as the temperature *changes*. [high stability] +/- 0.5 ppm ... applies to the entire temperature range, not per degree C. The REF CAL menu entry can be used to enter frequency-vs.-temp data that's supplied with each individual 1 PPM oscillator. This data is used in conjunction with an accurate temperature sensor to fine-tune the reference in 0.2-Hz steps as the temperature changes. Can the high stability reference also be calibrated at temperature to achieve 1 Hz, like the standard reference, or must one trust the calibration table which provides 0.2-0.5 ppm (10-25 Hz) accuracy? If calibrated at temperature, does the delta then offset other table entries (which might be used to accommodate crystal aging, for example), or are individual table entries calibrated? Can a calibration table be used with the standard reference? I can see some applications where 1 Hz, but you have to calibrate if the temp changes is better than 10-25 Hz, but you never touch it. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] Re: K3 Reference Oscillator
I've often wondered what the purpose of optional high stability reference oscillators in HF rigs is. A couple hertz between friends on CW, SSB, or AM isn't noticeable. Even PSK can handle slow drift quite well. Is there some other mystery mode or application that requires the rubidium oscillator-like stability people seem to spend money on and crave? (Folks using transverters on microwave bands??) -- Blog: http://thek3ngreport.blogspot.com/ ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
[Elecraft] Re: K3 Reference Oscillator
On Aug 29, 2007, at 10:16 AM, Mike S wrote: At 12:48 PM 8/29/2007, wayne burdick wrote... Maybe I wasn't clear on this. I said it was accurate to 1 Hz ... at the calibration temperature. That says nothing about what happens as the temperature *changes*. +/- 0.5 ppm (or +/- 1 PPM) is the most common high-stability reference option available for ham transceivers, K3 included. (And yes, this applies to the entire temperature range, not per degree C.) The K3 has an advantage over most transceivers in this regard. The REF CAL menu entry can be used to enter frequency-vs.-temp data that's supplied with each individual 1 PPM oscillator. This data is used in conjunction with an accurate temperature sensor to fine-tune the reference in 0.2-Hz steps as the temperature changes. So we're actually expecting something like +/- 0.2 ppm over temperature. But we're specifying it conservatively. I assume then that the high-stability option can also be calibrated to achieve 1 Hz through 6 meters at the calibration temperature, too (that was not stated)? You can achieve 1-Hz accuracy at the calibration temperature with either the standard or high-stability TCXO. The REF CAL menu entry can also be used to enter Freq-vs.-Temp data with either one, but this data is only provided for the high-stability unit. One could enter data for the standard oscillator, too, but you'd have to determine what data to enter by manually calibrating to a reference signal at each temperature point (5 degree increments). So you could set the high-temp CAL points on hot days and the low-temp CAL points on cold days. I'm not sure what overall temperature stability you could achieve using this method with the standard unit, but we'll be trying it at some point. Meanwhile, if you really want the best stability over temperature, I'd recommend the high-stability unit plus entering the data as supplied. Can the standard reference use a calibration table, so it might become more accurate as it is hand calibrated at different temperatures? Exactly -- see above. The manual will describe how to do this. 73, Wayne N6KR --- http://www.elecraft.com ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
Re: [Elecraft] Re: K3 Reference Oscillator
Mike, I believe you are mixing parameters. The K3 can be set to within 1 Hz, but the 0.5 ppm number applies the drift with temperature changes, and that is something quite different than accuracy. 73, Don W3FPR Mike S wrote: Can the high stability reference also be calibrated at temperature to achieve 1 Hz, like the standard reference, or must one trust the calibration table which provides 0.2-0.5 ppm (10-25 Hz) accuracy? If calibrated at temperature, does the delta then offset other table entries (which might be used to accommodate crystal aging, for example), or are individual table entries calibrated? Can a calibration table be used with the standard reference? I can see some applications where 1 Hz, but you have to calibrate if the temp changes is better than 10-25 Hz, but you never touch it. ___ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
